Is your interior plastic Faded?
I cleaned up my cowl screen. It had a faded spot on the very front so I wanted to give that SEM color coat another try. I found the 15243 Satin black at my PPG paint store. I cleaned it with hot soapy water first then used their prep spray and sand free spray. Then three coats of the satin black.
I took this picture with my camera at night...there are two lighted up areas that are not representing the results. Look at the overall satin black color.